Process for the preparation of monocyclic ketones and their alkyl derivatives having more than nine ring members



Patented Feb. 19, 1929 EJNI'TED STATES PATENT OFFICE.

LEOPOLD RUZIOKA, OE GENEVA, SWITZERLAND, ASSIGNOR 'TO M. NAEF & (10., O1

' GENEVA, SWITZERLAND, A COMPANY OF SWITZERLAND.

PROCESS FOR THE PREPARATION OF MONOCYCLIC KETONES AND THEIR ALKYL DE- RIVATIVES HAVING MORE THAN NINE RING MEMBERS.

No Drawing. Application filed November 19, 1926, Serial No. 149,539, and in Switzerland December 15, 1925.

In the prior application Serial No. 36,049 filed June 9, 1925, there is described a process of preparing monocyclic keton'es having more than nine ring members, which comprises heating a normal straight chain aliphatic d1- carboxylic acid salt ofthe fourth group of the periodic system especially thorium and cerium, said acid having a carbon chain containing more than ten carbon atoms, the car boxylic acid groups being linked to the end carbons thereof.

It has also been discovered that in a general manner for the preparation ofmonocyclic ketones having more than nine ring members and of their alkyl derivatives, from the dicarboxylic acids having more than ten carbon atoms in a normal chain or from their alkyl derivatives, the metals and the compounds of metals belonging to the rare earths may advantageously be employed.

According to the present invention didymium which belongs to the said metals, or its compounds such as for instance didymium oxide are employed either alone or mixed with another metal or metal compound belonging to the said group.

It is also advantageous to use a mixture of several metals ofthe third or fourth group of the periodic system, these mixtures being obtained artificially or otherwise. I Mixtures ofsthe above mentioned dicarboxylic .acids or their alkyl derivatives, which are prepared from the pure acids or as they are obtained in certain technical methods or from natural products, give, according to the present invention, mixtures of the ketones, or their alkyl derivatives, which, in this form, can also be employed in practice.

For obtaining the mentioned monocyclic,

ketones it is possible to heat directly the acids or the'acid anhydrides alone or in presence of metals or metal compounds at a comparatively high temperature, instead of first.

transforming the correspondin dicarboxylic acids into salts. In this case t e use of metals of the rare earths is also advantageous.

The ketones or their alkyl derivatives obtained by the described process can be used as perfumesor as primary materials for the preparation of other compounds.

technically important- Emample I.

The didymium salt of 3-methyl-tetradecane-L14-dicarboxylic acid is heated, preferably in a, vacuum, up to from 300 to 500 Centigrade and the distillate obtained therefrom is Worked up by fractional distillation. The fractions distilling at from 100 to 150 C. at a pressure of 0.5 mm. are then treated with semicarbazide or other reagent usually employed for isolating the ketones.

The pure 3-methyl-cyclopentadecanone can also be isolated by treating with acids the semicarbazone purified by crystallization in alcohol and melting at about 164 C.

The 3-methyl-cyclopentadecanone boils at 125 C. (at 0.3 mm.) and has a smell like that of natural musk and can therefore be used as a perfume as well as a' primary material for preparing other interesting technical compounds.

Example 2. 2 -methy1-tetradecane-1.let-dicarboxylic acid is heated up to above 300 to 500 centigrade and towards the end of the reaction preferably in a vacuum with didymium hydroxide in a quantity which does not suflice for com-.

pletely converting the acid into the normal salt. The product obtained is treated ac- (xln'ding to the method described in Examp e 1.

Example 3.

A mixture of the didymium and lanthanum salts of i-methyl-tetradecane-l.l dicarboxylic acid is heated and worked up as described in Example 1. The l-methyl-cyclopentadecanone obtained boils at about125 C. (at 0.3,

mm.) gives a semicarbazone melting at about 166 C. and has a smell practically like that of natural musk and can therefore be used as a perfume and for prepara-ing other interesting technical compounds.

Emample 4.

Example 5.

The didymium salt of tetradecane-lll-dicarboxylic acid is heated and worked up as described in Example 1. The cyclo-pentazdecanone is obtained which distills at about 120 C. (at 0.3 mm.) and melts at 63 C.

Ear/"ample 6.

Tetradecane-;-..ld-dicarboxylic acid is heated at about 300 to 500 U. towards the end of the reaction preferably in vacuum, with didymium hydroxide. The distillate resulting therefrom is worked up as described in EX.-

ample 5.

. Example 7.

The anhydride of tetradecane-LH-dican boxylic acid is heated to about 300 to 500 (1 towards the end of the reaction preferably in a vacuum with didymium hydroxide and worked up as described in Example 5.

Example 8.

A. didyinium salt of tetra-lld-dicarbbxylic acid is prepared by partially neutralizing this I acid with sodium hydroxide and precipitating with didymium chloride. The resultin didymium salt is decomposed by heating and worked up as described in Example 5.

Emample 9.

The didymium salt of octadecahe-LlS- dicarboxylic acid is heated preferably in a vacuum to about 300 to 500 C. and the resulting distillate is worked up by fractional distillation. The fraction distilling at from 140 to 180 C. (at 0.3 mm.) is then treated with semicarbazide or other reagent usually moaeer employed for isolating the ketones. The cyclononadecanone in a pure state can in this manner be isolated by treating the semicar bazone purified by crystallizatlon from alcohol and melting at 184 C. This ketoneboils at 160 C. (at 0.3 mm.) melts at 72 G. and has a smell which nearly corres onds to that 01 civetone. It can therefore e used as a perfume and as a primary material for pre.

paring other interestin technical compounds; by oxidizing t e cyclononadecanone with chromic acid heptadecane-LlT-dicarboxylic acid is formed.

Example 10. I

2. A process for the preparation of monocyclic ketones having more than nine rin members comprlsing heating a mlxture o' didymium salts and lanthanum salts of polymethylene dicarboxylic acids having more than ten carbon atoms in a normal chain the carboxylic acid groups being linked to the end carbons thereof.

, In testimony whereof I aflix m. signature.

\ LEOPOLD R ZICKA. 

